S000000285 [Member] Average Annual Total Returns

12 Months Ended

60 Months Ended

120 Months Ended

131 Months Ended

355 Months Ended

577 Months Ended

Dec. 31, 2024

Dec. 31, 2024

Dec. 31, 2024

Dec. 31, 2024

Dec. 31, 2024

Dec. 31, 2024

S&P Municipal Bond Index (reflects no deduction for fees, expenses or taxes)

Prospectus [Line Items]

Average Annual Return, Percent

^[1]

1.90%

1.20%

2.34%

S&P Municipal Bond Intermediate Index (reflects no deduction for fees, expenses or taxes)

Prospectus [Line Items]

Average Annual Return, Percent

^[2]

1.09%

1.11%

2.20%

Lipper Intermediate Municipal Debt Funds Classification Average (reflects no deduction for taxes or sales loads)

Prospectus [Line Items]

Average Annual Return, Percent

^[3]

1.81%

1.01%

1.80%

Class A

Prospectus [Line Items]

Average Annual Return, Percent

(1.29%)

0.26%

1.74%

Performance Inception Date

Jun. 13, 1995

Class A | After Taxes on Distributions

Prospectus [Line Items]

Average Annual Return, Percent

(1.31%)

0.25%

1.73%

Performance Inception Date

Jun. 13, 1995

Class A | After Taxes on Distributions and Sales

Prospectus [Line Items]

Average Annual Return, Percent

0.39%

0.74%

1.92%

Performance Inception Date

Jun. 13, 1995

Class C

Prospectus [Line Items]

Average Annual Return, Percent

1.01%

0.07%

1.40%

Performance Inception Date

Feb. 10, 2014

Class I

Prospectus [Line Items]

Average Annual Return, Percent

1.92%

1.07%

2.27%

Performance Inception Date

Nov. 29, 1976

[1]	An index designed to measure the performance of the tax-exempt U.S. municipal bond market.
[2]	An index containing bonds in the S&P Municipal Bond Index that mature between 3 and 15 years.
[3]	Represents the average annualized total return for all reporting funds in the Lipper Intermediate Municipal Debt Funds Classification.